The present invention relates in cooling systems, especially air cooling system and turbo wheel of the turbo expander
Cooling device (SU, A, 802740) comprising compressor connected with turbo expander by means of heat exchanger, cooling chamber and additional supercharger mounted between the heat-exchanger and cooling chamber.
Said device needs heat exchanger cooling system as the air temperature in the output of the compressor is high enough (about 120-140 degrees Celsius) thus increasing total power used by the cooling device. Besides if there is some amount of water steam it may lead to the freezing of the nozzle and working grate of the turbo expander.
The closest solution to the applied is the air cooling device (SU, A, 1290040) comprising compressor and turbo expander both mounted in the same shaft together with the regenerative heat-exchanger and cooling chamber with both fan and air cooler mounted inside.
Said device has limited parameters of cooling chamber temperature regulation along with weak freeze productivity and economy.
A turbo wheel (SU, A1, 059217) is known comprising bearing disk with blades and inter blade canals made by means of the nearest blades"" sides conjugated with meridian disk surface by means of flutes, said surface contain longitudinal micro canals with cross sections appearing as a part of a circle.
While working in conditions of humid air with negative work temperatures in the turbine flowing part and on the surface of inter blade canals of the working wheel in particular, it may lead to the ice film effect. Besides said turbine wheel provokes considerable hydro losses.
The principal object of the invention is the creation of an air cooling device providing the primarily air temperature decrease in the device up to the surrounding air dew point or 0 degrees C. correspondingly by means of air vaporization cooling and additional rarefy in the vaporization heat exchanger as well as turbine, turbo expander wheel of the said device the construction of which providing the device permanent work in the conditions of moist air and under the negative temperatures in the freezer.
Air cooling device comprises compressor, the first heat exchanger, turbo expander with turbine wheel, freezing chamber with both the first fan and air cooler mounted inside. According to the invention, said chamber is equipped with the second fan being mounted on the same shaft together with turbo expander, double cavity heat exchanger and the first moist separator. The first heat exchanger appears as double cavity and the first cavity of the vaporization heat exchanger, first moist separator, turbo expander, air cooler and the second cavity of the first heat exchanger are connected consequently to the input of the compressor.
The use of the double cavity vaporization heat exchanger in the device offered allows decreasing the temperature of the feeding air up to the dew point temperature of the surrounding air. That is, for example, if the surrounding air temperature is about +50 degrees C. and the relative humidity is about 40 percent, the air in the vaporization heat exchanger decreases its temperature to about +36 degrees C. Humidity separator makes it possible to considerately dry the moist air fed to the turbo wheel of the turbo expander.
For constant maintenance of the air vaporization cooling process it is necessary that the device should be equipped with water tank connected with the second cavity of the vaporization heat exchanger.
To intensify the process of both air vaporization cooling and create additional rarefying both the input and output of the second cavity of the vaporization heat exchanger are connected with the atmosphere by means of the second fan.
The device may comprise ejector, the first regulated valve and the second moist separator, the passive nozzle of ejector being connected with the atmosphere by means of both the second cavity of the vaporization heat exchanger and the first regulated valve, the active nozzle of the ejector being connected the second fan input. All these measures allow rarefying in the second cavity of the vaporization heat exchanger, thus additionally intensifying the process of vaporization cooling of the atmosphere air which leads to considerable reduce of its temperature.
To increase freezing productivity of the system additionally due to the feeding air pressure increase into turbo expander is possible. For this purpose said system comprises the third fan, both input and output of the second cavity of vaporization heat exchange being connected with the atmosphere by means of the third fan. The second fan input is connected with the compressor output, the second fan output is connected with the vaporization heat exchanger first cavity input.
The system may be equipped with the second and the third double regulated valve, the first cavity of the heat exchanger being connected with the second cavity of the first heat exchanger and compressor input, and the second being connected with the atmosphere by means of the fourth fan, the first cavity of the third heat exchanger being connected with the first cavity of the vaporization heat exchanger and the second fan output, while the second is connected with the atmosphere by means of the fifth fan. The second regulated valve is being mounted between the compressor input and output. In this case both the second heat exchanger and the fourth fan may be used as a conditioner.
For additionally air cooling and drying inside the system said device is additionally equipped with the fourth double cavity heat exchanger, the sixth fan and the third moist separator, the first cavity of the fourth heat exchanger being connected with compressor output and by means of the third moist separator with the second fan input, while the second cavity being connected with the atmosphere by means of the sixth fan.
To provide efficient work of the device under conditions of negative temperatures without moisture freezing on its elements said device is equipped with the first adsorbing moist separator, the first receiver, the third and fourth regulated valves, the first and the second reverse valves, both the first reverse valve and the first adsorbing moist separator being mounted in sequence between the first cavity of vaporization heat exchanger and the first cavity of the first heat exchanger, compressor output by means of the first receiver. While the fourth regulated valve is connected between the first reverse valve and the first adsorbing moist separator, the compressor input is additionally connected with the atmosphere by means of the third regulated valve, while the first receiver is connected with the atmosphere by means of the second reverse valve.
The compressor output of the proposed device may be connected with the first vaporization heat exchanger cavity, the device may be being equipped additionally with the fifth double cavity along with heat exchanger and the seventh fan. The first cavity of the fifth heat exchanger being connected with both compressor output and vaporization heat exchanger first cavity while the second being connected with the atmosphere by means of the seventh fan. In this case the device is able to implement the close cycle with the atmosphere air feeding.
The device is equipped with the second receiver, the second adsorbing moist separator, the third and the fourth reverse valves, the fifth, the sixth and the seventh regulated valves, the sixth regulated valve being mounted between the second cavity and the first heat exchanger being connected with compressor input by means of both fourth reverse valve and the second adsorbing moist separator. The compressor output is additionally connected between the second adsorbing moist separator and the fourth reverse valve by means of the third reverse valve, second receiver and the fifth regulated valve. The compressor output is additionally connected between the second adsorbing moist separator and the fourth reverse valve by means of the third reverse valve, second receiver and the fifth regulating valve, while compressor output is additionally connected with the atmosphere by means of the seventh regulated valve. Due to this effect an extra moist exclusion is provided.
To decrease considerately the noise level said device comprises the eighth and the ninth fans along with double cavity heat exchanger, the second cavity of the vaporization heat exchanger being connected with the atmosphere by means of the eighth fan. The first cavity of the sixth heat exchanger is connected with both input and output of the second fan, while the second cavity is connected with the atmosphere by means of the ninth fan.
The device may be equipped with the fourth moist separator and freeze accumulator, both being mounted in sequence between the turbo expander and air cooler. Such construction provides low temperature maintenance, i.e. in conditions of long time open front door of the freezing chamber.
The task set may be solved by means of the equipment of the air cooling device comprising compressor and the turbo expander with the turbine wheel, both being mounted on the same shaft, freezer with the first fan and air cooler mounted inside, in accordance with the invention, with double cavity vaporization heat exchanger being implemented as double cavity one. The first cavity of the vaporization heat exchanger along with the first moist separator, turbo expander, air cooler and the second cavity of the first heat exchanger are connected with the compressor input in sequence.
As the second way of its implementation the device may be equipped with the 10th fan. The second cavity of the vaporization heat exchanger being connected with the atmosphere by means of the 10th fan. The device may be equipped with the 7th heat exchanger and the 11th fan, the first cavity of the 7th heat exchanger being connected with both the compressor output and the first cavity of the vaporization heat exchanger. The second cavity is connected with the atmosphere by means of the 11th fan. Said device may be equipped with the water tank being mounted in the second cavity of the vaporization heat exchanger. Besides it may comprise both the 4th moist separator and freezer accumulator being mounted in sequence between the turbo expander and the air cooler. The device comprises the 8th regulated valve, the compressor input being additionally connected with the atmosphere by means of the 8th regulated valve.
The formation of the electric engine together with turbo expander and electric compressor may be mounted on the same shaft along with the turbo expander and the compressor. Said engine comprises the body containing turbo expander, electric engine and the compressor, electric engine rotor being implemented as turbine and compression wheels mounted cantileverly the shaft mounted in bearings. The cavity between the compressor wheel bearing and the electric engine being connected with the restart canal compressor entry. Regulated throttle may be being mounted inside the said restart canal. Such implementation of the turbo expander and the electric compressor allows increasing in economy and in freeze productivity of the device.
Mounted task may by solved by means of turbine wheel comprising bearing disk with the blades and inter blade canals implemented by means of the side surfaces of the nearest blades being conjugated with meridian surface of the disk by means of the flutes. The meridinal surface of the disk contains longitudinal micro canals with cross section as a part of the circle. In accordance with the invention radius of the said micro canal cross section is about 0.1-1.0 of the flute radius, the pitch between the canals is not more than two micro canals radiuses while the canal height is approximately 0.2-1.0 of the micro canal cross section radius.
Turbine wheel implemented accordingly to the invention allows raising its efficiency in ice formation conditions as well as lowering hydro losses by means of stream disturbance reduce in the inter blade canal.